This invention relates to colorimetry systems and, more particularly, to a colorimetry system with a ring of optic fibers arranged to illuminate the test surface on which the colorimetry measurements are to be made.
In colorimetry, it is conventional to illuminate the test surface to be measured and direct the light diffusely reflected from the test surface to photodetectors through different color filters. The electrical output signals of the photodetectors provide a quantitative measurement of the color of the test surface. The Gardner/Neotec Division of Pacific Scientific Company presently manufactures and markets colorimetry instruments in which light is transmitted to the sample from a light source and the light diffusely reflected from the sample is transmitted to three photodetectors with a different color filter placed in the light path to each photodetector. The output signals of the photodetectors are transmitted to the Gardner/Neotec XL-800 Series colorimeter console in which the signals from the photodetectors are converted to digital values and mathematic operations are performed on the digital values by a microprocessor for calibration and conversion into standard color index values.
The above described instruments give accurate quantitative color measurements as the eye perceives color. However, when the measurements are made on a textured surface, there may be some variation in the color measurement, depending upon the angular orientation of the test surface being measured. One of the objects of the present invention is to provide a colorimetry instrument in which the color measurements will not vary with the angle of the test surface even when the test surface is highly textured.